Hello @Mohit Singla ,
Thank you for contacting Microsoft QnA platform. Since you are getting Activate Windows Watermark on bottom right corner of your screen it means the Windows Installed did not activate during installation. In such cases you would need a valid product key or valid digital license associated with hardware for Windows 10 or Windows 11.
To activate Windows 11 using a product key, follow these steps:
- Open the Windows Activation menu by going to Settings > System > Activation.
- In the Activation state section, select Change in the “Change product key” row.
- Enter your 25-character product key in the dialog box and select Enter.
- Finally, click Activate. If your product key is valid, Microsoft will activate your Windows 11 device.
Remember that a product key is a unique code used to activate Windows. If you don’t have a product key, you can also activate Windows using a digital license, which is associated with your hardware and linked to your Microsoft account. Once your PC is connected to the internet and you log in to your Microsoft account, it should activate automatically.
I hope this helps you resolve this issue. Please "Accept the answer" if the information helped you. This will help us and others in the community as well.